I've had a lot of pisco sours in my time. There are the ones I drank during the two years I lived in Santiago, Chile. And there are all the ones I've had in the many years since I moved back to the U.S.—first because I was nostalgic for Chile, and then because it's just a good cocktail. Most of the pisco sours I've had in this country, though, I've made myself. I tried ordering them in bars for a while, but they just never tasted right, and eventually I gave up. I make a pretty good version, and in the last few days I've been experimenting more with the recipe.

The more research I do on pisco sours, though, the more confusing things become. For one, there's the fact that Chile and Peru both claim pisco as their national spirits, and make it slightly differently. In both countries pisco is distilled from grapes—essentially, they make wine and then run it through a still (I wrote more about exactly what pisco is here). But in Chile, the pisco is often (not always) aged in oak barrels, and water can be added after distillation to bring the spirit down to 40 percent alcohol—though again, this isn't always done; pisco can be bottled at anywhere from 30 to 50 percent alcohol. Peruvian pisco has to be bottled at distillation strength, and is never aged in wood.

Naturally, the pisco sours of the two countries are as distinct as the piscos themselves. Peruvian pisco sours always involve egg white and bitters; Chilean ones sometimes do. There are other differences, but there's so much variation even within traditional recipes in each country that trying to dissect their idiosyncrasies is near impossible, so I'm just going to focus on Chile.

The funny thing is that the pisco sour is the simplest of cocktails: it involves pisco, lemon or lime juice, sugar, and ice. In Chile, egg white and bitters are optional. But what kind of sugar? Lemon or lime juice? Should the ice be blended, or shaken with the drink and then strained?

Let's start with the blending. I've seen blended pisco sours, but it's rare, and I'm not a fan of them. So that's an easy one: shaken, not blended. On to the sugar. For some reason, most Chileans make pisco sours with powdered sugar. I assume that's because it dissolves easily, but it also contains cornstarch, which doesn't dissolve in water, so you end up with a bit of gritty white sludge at the bottom of your glass. On my last visit to Santiago I asked a friend of a friend—an engineer who also happens to be a bartender—about this practice. Powdered sugar shouldn't be used to make cocktails, he said. That doesn't explain why none of the other bartenders in Chile seem to agree with him, but it does support my preference for making pisco sours with simple syrup instead of powdered sugar.

Julia Thiel

The lemon/lime question is a harder one, complicated by the fact that they're not the same in Chile and the U.S. Lemons are pretty much the same in both countries (actually, Chile exports lemons to the U.S.), but I've never seen what we'd call limes there. What they do have, which I've never seen in the U.S., are limones de pica—small, round, thin-skinned limes from the Pica region of Chile. Some Chilean pisco sour recipes call for limon de pica, some for lemon; since I don't have access to the former here, I've always used lemons. But the book 40 Grados, about Chilean pisco, includes a pisco sour recipe that calls for "limon sutil," which is apparently what they'd call our limes (something I've been trying to figure out ever since I lived there). I decided to see whether the cocktail is better with lemons or limes.

I think that's the lime pisco sour on the left and the lemon on the right. They looked pretty much identical, though.

I used a fairly standard pisco sour recipe: two parts pisco (I used Capel Doble Destilado), one part lemon or lime juice, one part simple syrup, shaken with ice and then strained. (Many recipes call for three parts pisco rather than two, but both are common.) The difference was striking: the cocktail with lemon tasted smoother, sweeter, and more tropical—it seemed more citrusy, somehow. The one with lime was brighter and more sour, with a little bite, and I ended up preferring it.

Another night, I tried making the two pisco sour recipes from 40 Grados. One is traditional: three ounces pisco, one ounce simple syrup, one ounce lime juice, and an egg white, shaken with ice and topped off with a few drops of Araucano bitters, which are made only in Chile. I didn't have the bitters and didn't feel like messing around with separating eggs, so I made a basic version of the recipe, substituting Control C pisco, which I had on hand, for the Los Nichols pisco called for. It's a good recipe—simple, and it resulted in a pisco sour that tasted like it should: sweet, sour, and deceptively easy to drink. Next time I might add a touch less simple syrup.

The other recipe was a variation that involves simple syrup made with aji merquen (or merken), another Chilean specialty. It's a spice blend of sun-dried, smoked chiles (cacho de cabra peppers, specifically) crushed with salt, coriander seeds, and cumin. It's smoky and slightly spicy but not overly hot. I stock up whenever I visit Chile and use it in almost everything I cook—it's great. (Unfortunately, despite multiple articles that have been published over the years asking whether merquen is the next big thing, it hasn't caught on enough here to be readily available.)

Anyway, the book didn't include a recipe for the merquen syrup, so I put a couple tablespoons of the spice into a pot with a cup of sugar and a cup of water, heated it until it boiled, then turned off the heat and let it cool for about half an hour before I strained out the merquen. The recipe was almost identical to the other one, except that it called for Control C pisco and lemon instead of lime juice (as with the other recipe, I omitted the egg white and bitters). The merquen syrup made the cocktail smoky and a little earthy, a nice counterpoint to the bright citrus flavors. I was afraid it would be too spicy, but instead the syrup gave it a gentle heat that built over time.

I'm not about to stop making regular pisco sours, but the merquen version is better than I expected—and I'm excited about trying the syrup with other cocktails. If you want to make your own version but can't find merquen, try using a combination of smoked paprika and crushed red pepper.